The present invention relates to sheet material feeders, for example hoppers for feeding sheet material such as signatures, individual sheets or inserts from a pile.
U.S. Pat. No. 6,213,457, hereby incorporated by reference herein, discloses for example an apparatus for feeding flat products from a bottom of a pile using a sucker rotating on a sucker shaft.
U.S. Pat. No. 5,984,296, also hereby incorporated by reference herein, discloses a lifting sucker for removing a top sheet from a stack of sheet. An adjusting knob can alter a stroke distance and a consequent spacing to the sheets by various adjustable spacings of the cam paths.
U.S. Pat. No. 5,094,439 discloses a device for locking a suction nozzle of a sheet separating sucker on a top-feeding sheet feeder having an abutment attached to a governor foot drive.